So you lost a superstar employee to greener pastures – perhaps enticed by a promotion, a salary increase or an opportunity to take a new direction or explore a long-held passion. 

But now they’re keen to come back and you’ve just come across their updated resume in your applicant management system. What should you do?

Former employees who come back for a second round with an organisation are common enough that they’ve earned the nickname “boomerang employees”.

And although they tend to have good success in getting re-hired and promoted by their previous workplaces, there have been very few studies available to demonstrate whether or not this is a good idea – for either party.

Now three US academics have published one of the first major pieces of research into the topic in the prestigious Journal of Management, and the findings might surprise you. 

So if you’re thinking about re-hiring a gun ex-employee, here are some of the key things you may want to consider.

What makes “boomerang employees” so popular?

There are several reasons why you might be keen to get a former employee back on board, including:

1. They’re a known quantity. For many managers, it’s a case of better the devil you know. And knowing a candidate’s strengths and weaknesses without having to even meet with them can potentially save you all that shortlisting and interviewing time.

2. They already know the ropes. We know good onboarding is important to performance and retention, but with a new employee, you’ll have to start from scratch. Meanwhile, your boomerang employee can hit the ground running, saving you weeks or months of training and rookie mistakes. 

3. They know your stakeholders. Relationships matter, and someone who has already built relationships with key stakeholders is surely a good thing, isn’t it?

4. You know they’re committed to your cause. Hiring employees who have a passion for your purpose is especially important in the NFP sector. It helps employees find meaning in their work and increases retention. 

5. They’re a lower risk because they’ve already seen the good, the bad and the ugly of your organisational culture from the inside.

6. They’ll bring lessons. They’ve taken a break from your organisation and tried some new things so they’ll come back with fresh eyes, fresh new skills, fresh learnings and methodologies.

So how many of these reasons actually stand up to scrutiny?

What the data says

While the rationale in favour of boomerang employees seems to make total sense, the research paints a very different picture. The researchers followed the outcomes of almost 30,000 appointments over several years, comparing the results of hiring a newcomer, promoting internally or hiring a former employee to a management role.  

And the bottom line?

The perceived benefits above are largely imaginary.

In fact, new external hires and people promoted internally consistently outperformed ‘boomerang employees’ across a range of metrics, including:

1. Retention / loyalty: Contrary to expectations, boomerang employees were more than twice as likely to leave the organisation as newcomers or internal hires. 

This suggests that the retention issues that contributed to their first resignation are unlikely to be resolved and that once a person had left an organisation, they remained willing to consider leaving again as an alternative to addressing the issues making them unhappy. 

2. Job performance: Boomerang employees tended to perform at roughly the same level they were performing at when they resigned the first time. However, new employees and internal promotions outperformed them after just one year; and new employees performed “significantly better” over four years using a wide variety of measures, including goal attainment and customer service.

3. Impact on team: Boomerang employees were more likely to be repeatedly promoted than newcomers or internal promotions – despite being less effective in their roles and more likely to leave the organisation. 

That’s not good, because promoting poor performers has the potential to negatively impact the morale of other team members, who may feel that the re-hired employee is being unfairly rewarded. 

So should you ever consider re-hiring an employee?

Despite these findings, there are still some circumstances in which the research shows that it does make sense to re-hire a former employee:

1. If you only have short term goals. If the next 12 months are the only thing that matters to you, a former employee may help you get work done faster and more effectively, as they are likely to perform at a high level in the first year.

2. If you have a crisis. You have an immediate urgent resourcing need and you don’t have time to train someone new. You just need a safe pair of hands to see you through this crisis. In the short term, the predictability of your former employee’s performance represents a lower risk than the more unpredictable potential of a newcomer or internal hire. 

3. If no one has time or money to train them. Training and onboarding new employees is important but can be time-consuming and expensive. Hiring someone who already knows the ropes might help you side-step training costs, immediate demands on your time and weeks or months of an employee getting up to speed. 

4. If there are no other options. Not every organisation has other options to choose from when it comes to hiring. If you’re based in a regional or remote area, or if you’re hiring for a specialist role where candidates are few and far between, settling for a former employee may well be better than not hiring anyone at all.

Many organisations make a real effort to stay connected with former staff members in the hope that they might one day return to the fold. Alumni programs, email lists and events for former staff can take up a lot of time and effort.

But this new research shows that much of this may be a waste of time. If your NFP is looking for high-performing staff members who will stay with your organisation in the long term, hiring a former staff member probably isn’t going to be the best way forward.